Tenellia

Tenellia
A live individual of Tenellia adspersa, head end towards the right
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Order: Nudibranchia
Suborder: Aeolidacea
Family: Trinchesiidae
Genus: Tenellia
Costa, 1866

Tenellia is a genus of sea slugs, aeolid nudibranchs, marine gastropod molluscs in the family Trinchesiidae.

Taxonomic history

This was a small genus until a DNA phylogeny of the former family Tergipedidae resulted in most species of Cuthona being transferred to this genus. Miller (2004) restricted the genus Cuthona (Alder & Hancock, 1855) to the type species, C. nana (Alder & Hancock, 1842), and transferred to the genus Trinchesia the rest of the species previously included in Cuthona. Miller has been followed by some authors, and has not been followed by others - and there is currently much instability on the extension and contents of these two genera. Cella et al., 2016 hypothesised that the genus Tenellia should include many former Cuthona and Trinchesia species, with others being placed in new genera. Since then, there has been much shuffling of species between genera, many species being returned from Trinchesia to Tenellia, and others being placed in several smaller genera, Catriona, Diaphoreolis, Phestilla, and Zelentia.

In the most recent study, Korshunova et al., 2025 re-examined genetic, physical, evolutionary, and environmental characteristics of species within the suborder Aeolidacea, and proposed a massive recategorization of taxons. It was stated that the previous "lumping" of taxa together obscures the diversity and evolutionary origins of species. The extensive study proposed reversing several previous mass species reassignments between genera, reinstating taxa that had fallen to synonymy in previous papers, restricting genera, and suggesting guidelines for how to categorize species that likely belong to yet-undiscovered genera.

While The World Register of Marine Species (WoRMS) has cited Korshunova et al., 2025 across other taxonomic adjustments, in regards to Trinchesiidae, who is possibly the most controversed Aeolidean family with papers being published nearly every year from opposing camps, there has yet to be adjustments.

Species

According to Korshunova et al. (2025), species within the genus Tenellia include:

Species now moved to other genera include:

Controversed species currently represented by an alternate genus include:

References

  1. ↑ Costa, A. 1866. [for 1863]. Saggio sui molluschi eolididei del Golfo di Napoli. Annuario del Museo Zoologico della Universita di Napoli 3(2):59-80, pls. 1-3.
  2. 1 2 3 4 MolluscaBase eds. (2026). MolluscaBase. Tenellia A. Costa, 1866. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=138545 on 2026-03-04
  3. ↑ Cella, K; Carmona Barnosi, L.; Ekimova, I; Chichvarkhin, A; Schepetov, D; Gosliner, T. M. (2016). A radical solution: The phylogeny of the nudibranch family Fionidae. PLoS ONE. 11(12): e0167800.
  4. ↑ Korshunova, T.; Martynov, A.; Picton, B. (2017). Ontogeny as an important part of integrative taxonomy in tergipedid aeolidaceans (Gastropoda: Nudibranchia) with a description of a new genus and species from the Barents Sea. Zootaxa. 4324(1): 1.
  5. 1 2 3 4 Korshunova T.; Fletcher K.; Martynov A. (2025). The endless forms are the most differentiated—how taxonomic pseudo-optimization masked natural diversity and evolution: the nudibranch case Zoological Journal of the Linnean Society, Volume 204, Issue 4, August 2025, zlaf057